Refrigeration oil

Abstract

The present invention relates to a novel refrigeration oil comprising any one of the following three: (A) a polyol ester (POE) obtained by reacting one or more polyol(s) with one or more C 4-10 straight or branched chain fatty acid(s) and one or more C 5-10 fatty acid(s) having a specific structure, (B) a mixture of above (A) polyol ester and another polyol ester obtained by reacting one or more polyol(s) with one or more C 4-10 straight or branched chain fatty acid(s) and one or more C 5-10 fatty acid(s) having a specific structure, and (C) a mixture of one or both of the aforesaid (A) polyol ester and (B) polyol ester with a polyol ester obtained by reacting a polyol with the other fatty acid than the aforesaid C 5-10 fatty acid(s) having a specific structure.

The invention claimed is: 
     
       1. A composition comprising one or more polyol ester(s) (POE) obtained by reacting a polyol, a C 4-10  straight or branched chain fatty acid and a Neo-C 5-10  acid as a refrigeration oil for a difluoromethane (R32) refrigerant or a mixed refrigerant containing difluoromethane (R32) refrigerant, wherein the Neo-C 5-10  acid is in an acid portion in an amount of 1-50 wt %. 
     
     
       2. The composition according to  claim 1 , wherein the polyol is at least one selected from the group consisting of neopentyl glycol (NPG), 3-hydroxy-2,2-dimethylpropyl 3-hydroxy-2,2-dimethylpropanoate (HPHP), trimethylolpropane (TMP), ditrimethylolpropane (DiTMP), pentaerythritol (PE), dipentaerythritol (DiPE) and tripentaerythritol (Tri-PE). 
     
     
       3. The refrigeration lubricant composition according to  claim 1 , wherein the Neo-C 5-10  acid is in the acid portion in an amount of 10-30 wt %. 
     
     
       4. The composition according to  claim 1 , wherein the fatty acid comprises n-butyric acid, n-pentanoic acid, n-hexanoic acid, n-heptanoic acid, n-octanoic, n-nonanoic acid, n-decanoic acid, 2-methyl-butyric acid, 3-methyl-butyric acid, 2-ethylpentanoic acid, 2-ethylhexanoic acid, or 3,5,5-trimethylhexanoic acid and the like. 
     
     
       5. The composition according to  claim 1 , wherein the Neo-C 5-10  acid comprises neopentanoic acid, neohexanoic acid, neoheptanoic acid, neooctanoic, neononanoic acid, or neodecanoic acid, or mixture of each of the aforesaid acid(s). 
     
     
       6. The composition according to  claim 1 , wherein the polyol ester is miscible with the difluoromethane (R32) refrigerant or the mixed refrigerant containing difluoromethane (R32) refrigerant at a temperature of higher than −50° C. and less than 15° C. (20% of a polyol ester in a refrigerant) according to ANSI/ASHRAE Standard 86-1994, and has a kinematic viscosity between 22 and 320 cSt at 40° C. according to ASTM-D445. 
     
     
       7. A refrigeration lubricant composition comprising the composition according to  claim 1 , and a difluoromethane (R32) refrigerant or a mixed refrigerant containing difluoromethane (R32) refrigerant. 
     
     
       8. The refrigeration lubricant composition according to  claim 7 , wherein the refrigeration oil and the refrigerant are used in an amount of 1/99-50/50. 
     
     
       9. The refrigeration lubricant composition according to  claim 7 , further comprising extreme pressure additives, metal deactivators, acid scavengers, anti-oxidants, or other synthetic refrigeration lubricants. 
     
     
       10. The refrigeration lubricant composition according to  claim 9 , wherein the other synthetic refrigeration lubricants are polyalkylene glycols (PAG) or polyvinyl ether (PVE), wherein the ratio of the polyol ester included in the refrigeration oil to the PAG or PVE is between 100:0 and 60:40. 
     
     
       11. The refrigeration lubricant composition according to  claim 10 , wherein the extreme pressure additives are added in an amount of 0-4 wt %, the metal deactivators are added in an amount, of 0-0.5 wt %, the acid scavengers are added in an amount of 0-2 wt %, and the anti-oxidants are added in an amount of 0-1 wt %.